Hillary was around federal government her whole adult life and at the highest level. This fact is what she incorrectly claims makes her presidential material. She is also a lawyer, surrounded by government lawyers. There’s no way she did not know that what she was doing in setting up an outside server was in violation of the law, not to mention public trust.
Ignorance of the law is not a viable defense. Trying telling the officer you didn’t know the speed limit was 35 when you get pulled over for doing 50.